1. Field of the Invention
The present description relates to a method of forming an organic light emitting pattern and an apparatus for forming the organic light emitting pattern of an organic electro-luminescence display, and more particularly, to a method of forming an organic light emitting pattern and an apparatus for forming the organic light emitting pattern using a sublimation type thermal transfer method.
2. Description of the Related Art
A current organic electro-luminescence display is a self-light emitting type and does not require a backlight unlike a liquid crystal display (LCD), and thus weight reduction and slimness thereof are feasible and the organic electro-luminescence display can be manufactured through a simple process to increase price competitiveness. Further, the organic electro-luminescence display has low voltage driving, high luminous efficiency, and a wide viewing angle, thus receiving attention as a next generation display.
The organic electro-luminescence display includes a plurality of pixels to display an image. Each pixel includes an anode, an organic emission layer, and a cathode. In the case where the anode and the cathode provide holes and electrons to the organic emission layer, the holes and the electrons are recombined in the organic emission layer to form an exciton, and light having a predetermined wavelength is formed while the exciton falls to a stable bottom state. Herein, lights having wavelengths corresponding to red, green, and blue colors may be formed according to a material characteristic of the organic emission layer.
In the organic electro-luminescence display, each organic emission layer implementing red (R), green (G), and blue (B) colors should be patterned for each pixel in order to implement full colors. Herein, a deposition process using a shadow mask may be used in order to pattern the organic emission layer for each pixel.
However, in the deposition process using the shadow mask, it is difficult to obtain a fine pattern and it is also difficult to apply the deposition process to a large area substrate due to a limitation of equipment. Further, since the shadow mask should be frequently replaced, there are problems in that a process time and process cost are increased. Further, since an interval between the substrate and a source should be increased to form a uniform thickness of the organic emission layer, there is a problem in that deposition using efficiency of a material forming the organic emission layer is reduced.
Accordingly, a sublimation type thermal transfer method using a thermal transfer substrate instead of the shadow mask has been developed. However, if localized heat is applied over a short period of time for a high resolution, it is difficult to deposit a high-quality organic layer due to a high sublimation ratio of the deposition material, and on the other hand, slow heating reduces the resolution.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.